let esprima = require('esprima');
var estraverse = require('estraverse');
var escodegen = require("escodegen");
let code = 'function ast(){}';
let ast = esprima.parse(code);
console.log(ast);
 estraverse.traverse(ast,{
     enter(node){
         node.name += '_ext';
     }
 });
let generated = escodegen.generate(ast);
console.log(generated);
